MERS (Middle East Respiratory Syndrome) is a severe pneumonia-like respiratory disease caused by a virus. It is different from SARS because MERS is caused by another subtype of the coronovirus.
Pneumonia is a general term for an inflammation of the air sacs of the lungs caused by an infection or chemical. With pneumonia, the lungs fill with fluid, which interferes with their ability to transfer oxygen to the blood. MERS is known as an atypical pneumonia because it is not caused by the usual bacteria or viruses.
MERS causes high fever, cough, and severe shortness of breath. The infection is thought to be spread by close contact with an infected person.